Improvement in turn-tables for swing-bridges



T. @CLARKE & A. oNzANo.

Improvement in Turn-Table. for Swing Bridges.`

N0. 132,254.. i Patented Oct. 15,1872.

I f. "'f I UNrTED TATEs i FFICE.

THOMAS O; CLARKE, OF PHILADELPHIA, ,AND ADOLPHUS BONZANO, OF

' PHCENIXVILLFQ ASSIGNORS TOV OLARKE,` REEVES @t CO., OF PHILADEL- APHIA, PENNSYLVANIA.

v- IMPROVEMENT IN TURN-TABLES FOR SWING-BRlDGESl Specication formingpart of Letters Patent No. 132,254, dated October l5, 1872.

To all whom 'it may concern:

Be it known that we, THoMAs C. CLARKE, of Philadelphia, and ADoLPHUsBoNzANo, of Phoenixville, Pennsylvania, have invented an Improvement inTurn-Tables for Swing- Bridges, of which the following is aspecification:

Our invention relates to an improvement in the turn-table for whichLetters Patentwere issued to A. Bonzano on the 21st dayof May, 1872, ourpresent improvements, which are too fully explained hereafter to needpreliminary description, being directed more especially to themaintenance of the rim in a true condition, and to the ready verticaladjustability of the said rim.

In the accompanying drawing, Figure 1 is a vertical section of ourimproved turn-table for swing-bridges, and Fig. 2 a plan view of part ofthe table.

A is the foundation-plate, containing a recess or sock'et for thereception of the lower end of the central pin or pivot B, the upper endof which enters and supports a substantial casting, D, to which acentral post, E, is

secured by bolts a, the latter passing through a hub, G, which can slideon the pivot-pin, and be raised or lowered on the same by means of thesaid bolts a a. To the top of the central post is fitted a flanged disk,H, referred to hereafter, and a similar flanged disk, I, is so connectedto the plate A that it can turn freely thereon without being permittedto move vertically.

Having described the parts which compose the nave of the turn-table, wewill now proceed to explain themode of connecting this nave to the rim,which consists, in the present instance, of an annular and comparativelyshallow girder, J. of cast-iron, resting on numerous rollers K, the pinsof which are connected to annular ribs b, of angle-iron, and also byinclined radial rods d tothe iiange of the disk I, the rollers bearingon a circular plate, M, resting on the foundation N. To this circularplate M is secured an annular rack, M', by the aid of which and a piniongearing into the teeth of the rack the turn-table is caused to revolvein a manner too well understood to need description.. A series of radialtie-rods,

iP, connect the annular girder to the iianged disk, and a series ofradial struts, Q, extend lfrom the hub G of the nave to the annulargirder. I

In the girder for which Letters Patent were issued to A. Bonzano on the21st day of May, `1872, similar struts extend from a permanent part ofthe frame to the rim, each strut being provided with an adj usting-screwbearing against the said rim, the vertical adjustment of which isaccomplished partly by the screws on the struts and partly by the radialrods which connect the nave to the rim.

While the desired vertical adjustment of the rim may be accomplishedwith accuracy by skillful engineers who are familiar with the structure,the screws between. the outer ends of the struts and the rim may be sooperated by unskilled attendants as to force the rim out of true,thereby impairing the' entire structure andrendering the gearingforturning the table defective in its operation; hence, in our presentinvention ,we discard the adjustable struts and .use permanent struts Q,each of which bears at one end directly against the hub G, and at theopposite end directly against the annular girder J, the rods P servingto confine the whole permanently together. As the rim is thus rigidlyand permanently connected to the nave there can be no fear of the formergetting out of true; at the same time the rim admits of being adj ustedvertically to a limited extent desired by turning the nuts of the boltsav a.

There are cases in which the nature of the foundation renders the useoi' a deep annular girder or rim, like that described in our aforesaidapplication, advisable; but we prefer, in

making an entirely new structure, to use a comparatively shallow girder,J, as being more easily retained in a true condition than a deep girder.For the shallow girder we build on the foundation, on which the centralplate H rests, an annular wall, N, on which the circular plate M rests,the foundation from the central plate outward having a slight downwardinclination, so that the pit formed by the annular wall may beeffectually drained, the waste water passing oft' through suitable pipesor ducts in the wall.

We claim as our inventionl. A turn-table in which an annular girder isconnected to a nave by radial rods P, and by permanent struts Q, tted ttone end direotly to the girder and at the other end directly to avertically-adjustable portion of the nave, as set forth.

2. The Within-described nave, consisting of the disk I adapted to thepermanent pivotplate, the pivot B supporting the casting D, post E, anddisk and the hub Gr forming abutments for the struts Q, und renderedvertically adjustable on the tially as set forth.

pivot, all substan-

